import { getCurrentInstance, reactive, shallowRef, watchEffect } from 'vue';
import type { Ref } from 'vue';
interface Params {
   excludeListeners?: boolean;
   excludeKeys?: string[];
   excludeDefaultKeys?: boolean;
}

const DEFAULT_EXCLUDE_KEYS = ['class', 'style'];
const LISTENER_PREFIX = /^on[A-Z]/;

export function entries<T>(obj: Recordable<T>): [string, T][] {
   return Object.keys(obj).map((key: string) => [key, obj[key]]);
}

export function useAttrs(params: Params = {}): Ref<Recordable> | {} {
   const instance = getCurrentInstance();
   if (!instance) return {};

   const { excludeListeners = false, excludeKeys = [], excludeDefaultKeys = true } = params;
   const attrs = shallowRef({});
   const allExcludeKeys = excludeKeys.concat(excludeDefaultKeys ? DEFAULT_EXCLUDE_KEYS : []);

   // Since attrs are not reactive, make it reactive instead of doing in `onUpdated` hook for better performance
   instance.attrs = reactive(instance.attrs);

   watchEffect(() => {
      const res = entries(instance.attrs).reduce((acm, [key, val]) => {
         if (!allExcludeKeys.includes(key) && !(excludeListeners && LISTENER_PREFIX.test(key))) {
            acm[key] = val;
         }

         return acm;
      }, {} as Recordable);

      attrs.value = res;
   });

   return attrs;
}
